Rubber accelerator



301mm H. rowEns, F PENNS GROVE, nnwftiniasn ASSIGNOR To Ell nu 'roi'v'r13B Patented Ma 12, 1931 1 STA T es P NT;

' LIE-Moons "8; COMPANY, on, WILMINGTON, DELA ARE, A GORP RATIQNQF DELAc WARE Patents 1,440,962, 1,440,963, and 1,440,964,

to Cadwell contain charts referring to groups represented by thefollowing formuand 1,440,964 .mention ithe metallic and 101- ganic saltsof several dithio carbamic acids amount of practice.

resulting from the action of carbon disulphide on certain aliphatic andaromatic amines, the substituted thiuram'monoand di-sulphides, thexanthogenates, and other similar-compounds. These compounds haveadvantages in that 'in general -a smaller accelerator causesvulcanization ina shorter time andat a lower temperature than can berealized with alarger amount of the older accelerators such as di-orthotolyl guanidine or ethylidine aniline in a longer time .and at ahigherltemperature. However, in mostcases they 'actsofl rapidly thatconvenient handling orthe rubber stocks prior tocuring is no't possiblewith-out scorch- These disadvantages have greatly limited the use ofthese compounds in general 'Cadwell also disclosestheuse ofdipiperidylthiuramdisulphide U 8. Patent 1,449, 59?) a chartgrefierringto the group represented y the formula NCS'-M gll s- (U. S. Patent1,510,652), and the metallic salt of a, dithioc'arhamate"( U. S. Patent1,513,122).

Although the piperidine salt oiipiperidyl dithionate has long been known1 as indicated RUBBER ACCELERAT OE 1927. Serial no. "190,383. a

by L'HofYman above, its use has been very limited-because iteiiectsvulcanization at temperatures below 100 C, and extremelyrapidlyattemperatures above'100C. Other compounds which have been prepared and which-have certain accelerating values include oXazinessuchasbenzomorplioline I V g V (Ber 32,7 andnaphthalene morpholine UHwOH Richter v01. Iii, .261. 7 i

My invention has as an object the use of new 'organi'c compounds asaccelerators of vulcanization and the process of producing new rubberproducts therefrom; Another ,4

object 'ofmy invention is a processwhereby vulcanization 1s eiiected inhot air cures with new organic accelerators which. are not retarded bythepresence of lead salts in the rubber IlllX- A further object ofmyinvention is a rubberaccelerator which may be used for vulcanizationwith advantages at; temperatures fi-om C. to 145 C. A still furtherobject of my new organic compoundswhich may be pre-T pared fromrelatively inexpensive intermediates. i

I :have found morpholyl reaction of carbondisulphide on morpholine, asindicated by the equation that the morpholine" salt of CH CHz Benz-o 11/the manufacture ofboots and shoes since it effects vulcanization rapidlyin, a dry heatat temperatures of to As a measure invention-is the use of'dithionic acid, prepared by the butispractically'inactive at 100 C. Itis further-particularly adapted for use in of relative activity a rubberstock containing 0.5% of piperidyl piperidine dithionate is overcured in45 minutes at 5 pounds steam pressure, while 0.5% of morpholylmorpholine dithionate gives a good cure in 45 minutes at 20 pounds steampressure.

In connection with my study of morpholine derivatives the morpholinesalt of morpholyl dithionicv acid has been oxidized with alcoholiciodine to give a new thiuram disulphide which probably has the followingformula:

The following example represents the pre ferred method of preparing amorpholyl dithionate, but it is to be understood that this is onlyillustrative.

Eighty-six pounds of morpholine is-mixed with one hundred pounds ofether cooled to 5 (1., in a kettle equipped with agitation, brine coils,and a reflux condenser. Forty pounds of carbon disulphide is added tothe cooled, agitated solution, using the usual precautions for handlingthis material. The morpholine salt of morpholyl dithionic acid separatesas a white crystalline powder insoluble in ether and soluble in water,in practically quantitative yields. A sample of this material tested ina rubber mix gives the following cures:

CHI-CH NHzI \CHr-OHZ/ Parts Smoked sheet- Sulfur 3.5 Zinc oxide 3.0Morpholyl dlthionate 0.5

P f tl l El ressure s reng on- Time minutes pounds 600% at break gationlbs/sq. in.

Besides the morpholine salt of the morpholyl dithionic acid, I have alsofound that it'is possible to prepare other salts of morpholyl dithionicacid such as the sodium, zinc, lead, and potassium salts, most probablyrepresented by the following formulas:

\ This thiuram disulfide, prepared by the oxidation of either themorpholyl or metal salts of morpholyl dithionic acid, in alcoholsolution with KCN gives a product which is believed to be athiuram-mon'o-sulfide, most probably represented by the followingformula:

It is believed that when a salt of morpholyl dithionic acid such as thepotassium salt is treated with a cyanogen halide (CNCl) that the thiurammono sulfide, represented most probably by the above formula, is alsoformed, according to the following equation:

All of these products have been found to be very active accelerators ofvulcanization. As many apparently Widely different embodiments of thisinvention may be made without departing from the spirit thereof, it isto be understood that I do not limit my self to the foregoing examplesor description, 7

except as indicated in the following patent claims.

' I claim: 1. As a new product, a compound containing the grouping 2. Asa new product, a compound containing the grouping in which R is anorganic radical.

3. As a new product, a cyclic compound containing the grouping oHioH SNds-R orr2cH/ in which R represents a substituent of the classconsisting of the radical action product of carbon bisulfide and mor- Vpholine.

5. In the vulcanization of rubber, the step of incorporating therewith,prior to vulcanization, a reaction product of the type set forth inclaim 3.

6. In the vulcanization of rubber, the step of incorporating therewith areaction product of the type set forth in claim 4.

7. The rubber product obtained by the vulcanization of rubber in thepresence of a compound of the type set forth in claim 3;

8. The rubber product produced by the vulcanization of rubber in thepresence of the reaction product of carbon bisulfide and morpholine.

9. The process of treating rubber, which comprises incorporating withthe rubber a vulcanizing agent and a morpholine derivative of the typeset forth in claim 3 and thereafter subjecting the mixture tovulcanizing temperatures. p

10. The process oftreating rubber, which comprises incorporating withthe rubber a vulcanizing agent and about 0.5% of the reaction product of1 mole of carbon disulfide and 2 moles of morpholine and thereaftervulcanizing at 20 pounds steam pressure.

In testimony whereof I afiiX my signature;

- V DONALD H. POWERS.

